Re-winding device for the paper for teleprinter machines and printing machines in general

ABSTRACT

A device for rewinding the paper strip on a teleprinter machine is disclosed, including a motor driven rewinding roller and motor control means sensitive to the length of a portion of the paper strip comprised between the rewinding roller and the teletype&#39;&#39;s printing roller to intermittently rotate the rewinding roller and so wind up the paper. The changing length of the paper strip portion causes oscillation of a lever coupled to a switch which turns the motor on or off depending on the length of the strip portion. Means are also provided to monitor the diameter of the feed strip roll.

United States Patent Sandrone et al. Jan. 1, 1974 1 1 RE-WINDING DEVICE FOR THE PAPER 1,378,887 5/1921 Martin 242/57 FOR TELEPRINTER MACHINES AND .2 y a i;

. ong on... PRINTING MACHINES IN GENERAL 1,955,798 4/1934 Fassmann 242/672 Inventors: Bruno Sandrone; Antonio Toniolo,

both of Ivrea, Italy Assignee: Ing. C. Olivetti & Co. S. p. A., lvrea (Torino), Italy Filed: July 2, 1971 Appl. N0.: 159,273

Foreign Application Priority Data July 3, 1970 Italy 69300 A/7O References Cited UNITED STATES PATENTS Shangle 242/57 Primary Examiner-George F. Mautz Assistant Examiner-Edward J. McCarthy Attorney-Harold J. Birch et a].

[57] ABSTRACT A device for rewinding the paper strip on a teleprinter machine is disclosed, including a motor driven rewinding roller and motor control means sensitive to the length of a portion of the paper strip comprised between the rewinding roller and the teletypes printing roller to intermittently rotate the rewinding roller and so wind up the paper. The changing length of the paper strip portion causes oscillation of a lever coupled to a switch which turns the motor on or off depending on the length of the strip portion. Means are also provided to monitor the diameter of the feed strip roll.

16 Claims, 8 Drawing Figures PATENTEU JAN 1 4 sum 1 or 4 INVENTOR W l fa? ATTORNE RE-WINDING DEVICE FOR THE PAPER FOR TELEPRINTER MACHINES AND PRINTING MACHINES IN GENERAL The present invention related to a device which allows the strip of paper printed by a teleprinter or another machine to be re-wound as the strip emerges from the carriage of the machine, forming a roll which can be extracted at any desired moment with ease and rapidity from the device.

As is known, the strip of paper printed by a tele printer or other printing machines, which is usually allowed to emerge freely from the carriage of the teleprinter machine during the operation thereof, gathers on some support surface in the proximity of the carriage or is torn off when its length becomes excessive. In both cases there are disadvantages which can cause trouble during the operation of the teleprinter machine or which can make the preservation of the information written on the strip not very rational.

Thus the encumberance caused by the high volume of strip which gathers in the vicinity of the teleprinter can be troublesome for the operator, whilst the fre quent tearing off of the strip in order to prevent or reduce the formation of such a high volume requires fre quent intervention by the operator. Furthermore, the secrecy of the information printed on the strip is not absolutely ensured, this being easily accessible even in the periods in which the teleprinter is not in operation. Finally, if the printed strip has to be preserved, it has to be wound to form a roll or else the various portions into which it has been torn have to be preserved, by effecting in the first case an operation which requires some considerable time and in the second case an operation which is not very rational.

The object of the present invention is to provide a rewinding device which allows the aforesaid disadvantages to be eliminated.

According to the present invention, there is provided a re-winding device for the strip of paper emerging from a teleprinter machine or other printing machine, wherein the strip is re-wound on to a re-winding roller driven by an electric motor revolving in intermittent manner and the rotation of which is controlled by con trol means sensitive to the length of strip comprised between the roller and the point of emergence from the machine.

The invention will be described in more detail, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view, partially sectioned of a re-winding device embodying the present invention, mounted on a teleprinter machine of which some parts of the carriage are visible;

FIG. 2 shows, diagrammatically, a side view of the main parts of the device of FIG. 1;

FIG. 3 shows, diagrammatically, the relative position in which some parts of the device of FIG. 2 are arranged, in a first operating position of the device;

FIG. 4 shows, diagrammatically, the relative position in which some parts of the device of FIG. 2 are arranged, in a second operating position of the device;

FIG. 5 is a partial perspective view of a part of the means which drive the opening and the closure of two microswitches with which the device is provided;

FIG. 6 is an exploded perspective view of the driving means for rotating the roller on which the strip of paper is re-wound;

FIG. 7 shows a longitudinal section of a clutch with which the means of the previous Figure are provided; and

FIG. 8 is a perspective view of a gear of the driving means showing the teeth of the clutch.

In the embodiment shown in FIG. 1, the re-winding device 1 is mounted on a teleprinter machine of which the carriage 2 is visible with its platen 3 with which character-bearing wheels, not shown, co-operate.

The device comprises a pair of fixed lateral walls 4 and 5, connected one to another by cross-pieces which are not shown, a. feed roller 6,. on which there is mounted a paper strip roll 7 and a re-winding roller 8 on which, during the operation of the device, a paper strip roll 9 gathers. The roller 6 is mounted for rotation on the side walls 4 and 5 and can be inserted in the device and removed from the same with ease and rapidity, in the manner which will be described, whilst the roller 8 rotates in a swinging frame 10 comprising a pair of flange plates 11 and 12, connected one to another by an upper wall 13 and hinged, by means of pins 14, to the side walls 4 and 5.

Arranged between the side walls 4 and 5, downstream of the roller 6 and along the course of the strip of paper 15, is a guide plate 16 and, upstream of the rewinding roller 8, is a fixed bar 17, both arranged to cooperate with the strip of paper which, during the operation of the device, runs over them. A moving bar 19 in the front part of the device of FIG. 1, has its ends fixed to a pair of levers 20 and 21, each of which is hinged to one of the. plates 11 and 12 by means of pins, on which only the pin 22 of the lever 20 is visible in FIG. I.

A cam 23 is fixed near the end wall of the lever 20 (FIGS. 1 and 2) and this lever is normally held in the position shown in FIG. 2 under the action of a helical spring 24 which tends to cause it to rotate in an anticlockwise direction, its ends being fixed to an arm 25 of the lever and to a point of the plate 11. In the said position the lower end 26 of the cam 23 rests on a tongue 30 (FIG. 1) of a lever 31 hinged, by means of a pin 32 (FIG. 2), to the side wall 4 and arranged to cooperate with a control button 33 of a microswitch.34 (FIG. 1) fixed to the side wall 4.

The cam 23 (FIG. 2) has a curved profile 35, an upper recess 36 and a curved slot 37 with which there co-operates a pin 38 of a lever 39, hinged by a pin 40 to the side plate 11.

The lever .39 is provided with an arm 41 having an operating tongue 42 and with a lower finger 47 (FIGS. 1, 2 and 5) provided with a pin 48 to which there is fixed the end of a helical spring 49 whose other end is fixed to another pin 50 of a lever 51 which can oscillate about a pin 52 fixed to the plate 11. A tongue 53 (FIG. 5) of the lever 51 is arranged to co-operate with a control button 54 of a second microswitch 55 arranged at the side of the microswitch 34 and also fixed to the side wall 4 (FIG. 1) Hinged on each of the plates 11 and 12 by means of the pins 40 of the levers 39, is a lever 64 having a substantially T" shape and provided, in the lower part, with a notch 65 (FIG. 2) arranged to cooperate with a corresponding projecting pin 66 fixed to one of the side walls 4 and 5; a helical spring 67 (FIG. 2), fixed to each lever 64 and to the corresponding plate 11 or 12, normally keeps the bottom of the notch 65 against its pin 66. At the upper part of the lever 64 and on opposite sides with regard to the pin 40 there are formed two tongues 68 and 69 which serve for the operation of the lever.

The plates 11 and 12 are provided with recesses 70 arranged to accommodate the end pins 72 of the winding roller 8. An arm 71 of each lever 20 comes to rest on the corresponding end pin 72, when the lever is in the position of FIG. 2.

One of the end pins of the roller 6 is housed in a hole (not shown), in the side wall whilst the other one, indicated by 73 (FIG. 1 and 2), rests on the bottom of a slot 74 formed in the side wall 4. A latch 75, hinged with a pin 76 to the wall 4, has a finger 77 (FIG. 2) normally held against the pin 73 by a helical spring 78, whose ends are fixed to a pin of the wall 4 and to another finger 79 of the latch. In the position of FIG. 2 the spring therefore thrusts the latch 75 in the anticlockwise direction. A third finger 80 of the latch 75 is capable of stopping against a pin 180 of the plate 11 when the latch 75 is rotated in the clockwise direction into the position shown in broken lines in FIGS. 2. In this position the spring 78 passes over the pin 76 and thus urges the latch 75 in the clockwise direction.

Fixed to a bar 81 (FIGS. 1 and 2), revolving between the side walls 4 and 5, is a feeler arm 82, whose end carries a small wheel 83 arranged to co-operate with the roll of paper 7, and a second arm 84 whose end rests on the lever 31 which effects the opening and the closure of the microswitch 34.

The winding roller 8 is caused to rotate by an electric motor 85 (FIGS. 1 and 6) arranged on the side wall 5 of the device and connected to the roller by means of a transmission comprising three pairs of toothed wheels 86, 87 and 88 and a clutch 89. The toothed wheels of each pair'mesh one with another and on the face of the last toothed wheel 90 of the pair 88 which faces the roller 8, there is arranged a pair of teeth 91 (FIGS. 6 and 7), each of which is arranged to engage a corresponding radial projection 92 integral with the pin 72 of the roller itself. The toothed wheel 90 is integral with a cylinder body 93, movable axially within a sleeve 94, fixed, for example by means of screws, to the side wall 5 of the device. A helical spring 95, arranged inside the sleeve normally urges the body 93 to rest against the projections 92. The body 93 (FIG. 7 is rotatable on a stem 96 integral with an end disc 97 and is held on the stem by a circlip 98.

The end disc 97 (FIG. 6) is provided with a small handle 99 having a tongue 100 and with an axial tooth 101 arranged to co-operate, alternately, inside one of two axial cavities 102 and 103 formed in the sleeve 94. The axial langth of the cavity 102 is greater than that of the other one end, when the tooth 101 is in the cavity 102, the tongue 100 of the handle 99 is arranged underneath the tongue 68 of the lever 64, as is indicated by a broken line in FIG. 6.

The roller 8 comprises a casing 105 of substantially cylindrical shape which has a longitudinal slot 106 and a pair of end discs 107 and 108 spanned by a bar 109 whole ends project as the pin 72 and a corresponding pin at the other end. The discs 107 and 108 have cylindrical plugs 110 jammed inside the casing 105. The disc 107 has a tooth 11 1 which fits into the slot 106 in order to constitute a key.

Conveniently a cover 112 (FIG. 2), hinged at 113, is arranged to close the device. The cover can be provided with a lock.

In operation, feed roller 6 (FIG. 1), on which there has been inserted a roll of paper 7, is mounted on the device by inserting one of its end pins inside the corresponding hole in the side wall 5 of the device, whilst the other end pin 73 is introduced into the slit 74 of the wall 4. This pin engages the arm 79 of the latch which is thus snapped into the full-line position of FIG. 2. If on the latch should be already in this position, it can first be moved manually into the position shown in broken lines.

The strip of paper 15 which unwinds from the roll 7 is fed over the guide plate 16 and then under the platen 3 and between this and the character-bearing wheels (not shown) of the carriage 2 (FIG. 1). Then the emergent strip 15 is fed upwards again and over cross-pieces 114 with which the carriage is provided.

At this point, by pressing on the tongues 68 of the two levers 64, these are rotated by a small angle, unlocking the notches 65 (FIG. 2) of the levers from the pins 66, and the swinging frame 10 can be swung upwards into the position shown by broken lines in FIG. 2. In such a position the recesses 70 being turned upwards, it is easy to insert into these the winding roller 8 and to insert into the slot 106 the end of the strip of paper 15 after having caused it to wind round the bars 17 and 19, so as to form a loop 115 (FIG. 1). The course along which the strip is arranged during such an operation is shown in dot-dash lines in FIG. 2. The frame 10 is swung down again into the position of FIG. 1. To set the device in motion it is necessary to press on the tongue 42 of the lever 39 so as to cause it to turn in the clockwise direction: This causes the finger 47 (FIG. 5) to move over-centre with regard to the pin 52 of the lever 51. The spring 49 therefore pulls the lever 51 in an anticlockwise direction, whereby the tongue 53 presses on the control button 54 of the microswitch 55, which accordingly energizes the electric motor 85.

The motor (FIG. 6) can drive, through the pairs of toothed wheels 86, 87, 88 the roller 8, bringing about the winding of the strip 15 on to the roller. As a consequence of such a rotation the length of the loop (FIG. 1) is reduced, the lever 20 rises until it moves into the position of FIG. 4, in which the manual operation of the tongue 42 of the lever 39 can cease since the pin 38 of the lever 39 now rides on to the upper tract of the profile 35 of the cam 23, which keeps the lever 39 rotated into the position shown in FIG. 4, in which the microswitch 55 is closed and the electric motor rotates.

The rotation of the lever 20 continues until it assumes the position of FIG. 3, in which the pin 38 of the lever 39 stops at the bottom of the slot 37 of the cam 23. During the rotation of the lever 20, from the position of FIG. 4 to that of FIG. 3, the pin 38 of the lever 39 co-operates with the profile 35 and with the slot 37 of the cam 23 whose profile is such as to cause the lever 39 to rotate in the anticlockwise direction, moving, at the end of the aforesaid rotation, the finger 47 to the right with regard to the pin 52 (FIG. 5) of the lever 51. In such a position the spring 49 turns the lever 51 clockwise; the tongue 53 is raised and the microswitch 55 is opened, stopping the motor 85.

During the operation of the teleprinter machine, its paper feed means cause the strip 15 to advance round the platen 3. The emergent strip is pulled over the upper wall 13 (FIG. 1) of the frame 10 under the action .tq s as .thsrs l r .8..-

of the pull exerted on the loop 115 by the moving bar 19 and produced by the spring 24.

If accidentally there is a breakage of the strip of paper 15, the lever 20, no longer supported by the loop 115, rotates in the anticlockwise direction beyond the position shown in FIG. 4 until the lower end 26 of the cam 23 presses on the tongue 30 and actuates the but ton 33 of the microswitch 34. This switch provides a suitable warning signal.

When the lever is in the position with the end 26 of the cam 23 on the tongue 36 of the lever 31, the pin 38 of the lever 39 enters the recess 36 of the cam. The lever 39 rotates in the anticlockwise direction, so as to cause the lever 51 to rotate in the clockwise direction and to open the electrical circuit controlled by the microswitch 55, stopping the motor 85 and therefore the Rotation of the lever 31 is also controlled by the arm 84 integral with the bar 81, when the diameter of the roll of paper 7 reaches a predetermined reduced diameter, as is clear from FIG. 2. Also in this way the switch 34 can provide a signal which indicates that the strip 15 at hswll of P p is es p e y K 39i In order to extract the re-winding roller 8 with the roll of paper 9 re-wound on it, it is necessary to open the clutch 89 (FIG. 6), as is shown in FIG. 6. To this end, the handle 99, which when the clutch is closed finds itself in the position shown in broken lines, is rotated in the anti-clockwise direction, moving the tooth 101 from the cavity 102 into the cavity 103. In this way there is imparted to the stem 96, besides a rotation, an axial translation which pulls the cylindrical body 93, and hence the teeth 91, away from the radial projections 92 integral with the winding roller 8. At this point, by pressing the tongues 68 of the levers 64, and with an operation completely the same as that already described, one unlocks the frame 10 and one causes it to rotate in the clockwise direction by moving it into the position shown in broken lines in FIG. 2. The roller 8 with the roll 9 can be pulled away from the slot 70 and extracted from thedevice.

It is observed that the rotation of the levers 64 to unlock the frame 10 can be effected only after the end disc 97 has been rotated in the anticlockwise direction, in order to move the tooth 101 from the cavity 102 to the cavity 103 and to open the clutch 89. In fact, when the clutch 8'9 is closed, the tongue 100 of the handle 99, by placing itself underneath the tongue 68 of the lever 64, prevents the rotation of the lever 64 associated with the flank 12.

In order to initiate any of the operations for the extraction or the insertion of one of the rolls of paper 7 or 9 it is always necessary to open first the cover 112 (FIG. 2) of the device. Since the use of a key or the like is required for the opening of the cover, the device allows one to preserve with a certain secrecy the information printed by the teleprinter machine and recorded on the roll ofpaper 9.

ll. A re-winding device for a st'rip of paper for teleprinters and printing machines in general, including a printing roller over which the paper strip passes for writing thereon, a re-winding roller for rewinding the printed strip, an electric motor drivingly coupled to said rewinding roller, a feeding circuit coupled to said motor and operable to supply drive current thereto, a switch for operating said feeding circuit, and a bar around which the strip forms a loop, wherein the improvement comprises a first lever connected to said bar and oscillating between a pair of positions, a first posi tion of said pair indicating a predetermined minimum length of said loop, a second position indicating a predetermined maximum length of said loop, a cam fixed to said first lever for driving the rotation of a second oscillating lever, one end of said second oscillating lever being connected elastically to one end of an oscillating keeper to operate an actuating button of said switch when said first lever reaches said second position.

2. A re-winding device in accordance with claim 1 including a circuit for generating a predetermined strip-break indicating signal, said] circuit including a second switch cooperating with said first oscillating lever for generating said signal, said first lever assuming a third position different from said first and second positions wherein said strip loop is of maximum length when said strip loop breaks;

3. A re-winding device as claimed in claim 2 wherein said second switch includes an actuating button cooperating through an element with one end of said cam,

said one cam end coming to rest against said element when said first oscillating lever assumes said third position.

4. A re-winding device as claimed in claim 2 including a feed strip roller carrying said paper strip in a roll in said machine, and means sensitive to the diameter of said feed paper strip roll and cooperating with the actuating button of said second switch for actuating said switch when the diameter of said feed strip roll reaches a predetermined value.

5. A rewinding device in accordance with claim 4 wherein the means sensitive to the diameter of the strip roll comprise a third oscillating lever, one whose ends cooperate with the outer surface of said feed strip roll and the other end rests on said element cooperating with the actuating button of the second switch.

6. A re-winding device as claimed in claim 1 comprising a fixed frame integral with the machine and on which there is mounted revolvingly the roller which supports the said feed strip roll, and an oscillating frame hinged to the fixed frame and comprising substantially an upper wall and two lateral flanks said rewinding roller being revolvingly mounted on said oscillating frame.

7. A re-winding device in accordance with claim 6, including a locking member hinged to the oscillating frame for manually locking said oscillating frame and including a slot located on said locking member to cooperate with a projecting part integral with the fixed modatethe end pins of therewinding roller wherein the said gearing is connected axially, but not torsionally, to a drive element operable manually and arranged to assume a first position in which the clutch is open and a second one position in which the clutch is closed.

12. A re-winding device in accordance with claim 1 1, wherein the driving element includes a tooth extracted in it and cooperating with a cam having first and second axial adjacent cavities, a helical spring being arranged which thrusts the said gearing towards the re-winding roller holding said tooth within said cavities.

13. A re-winding device in accordance with claim 11, wherein the driving element is arranged to co-operate with the locking member of the oscillating frame, so as to prevent the unlocking of the oscillating frame when the clutch is closed.

14. A re-winding device in accordance with claim 13, wherein said driving element includes a projecting part arranged to place itself on the trajectory of the locking member which drives the unlocking of the frame itself, when the driving element is in said second position in which the clutch is closed.

15. A rewinding device for a strip of paper for teleprinters and printing machines in general, including a platen roller over which the paper strip passes for writing thereon, said platen roller being rotatable for line spacing said paper strip, a rewinding roller for rewinding the printed paper strip, an electric motor drivingly coupled to said rewinding roller, a switch operable for supplying electric power to said motor, a bar around which the strip forms a loop and reciprocably movable between a pair of positions, a first position of said pair corresponding to a predetermined minimum length of said loop, a second position corresponding to a predetermined maximum length of said loop, a member connected to said bar for concomitant movement, an element shiftable from a home position to an operating position to operate said switch, and intermediate means connecting said member and said element for suddenly shifting said element from said home position to said operating position when said member reaches said second position and from said operating position to said home position when said member reaches said first position.

16. A re-winding device according to claim 15, wherein said member is formed of a first lever and said element is formed of a second lever fulcrumed on a stationary pivot, said intermediate means including a tension spring connected between two ends of said levers, the rotational force of said spring on said second lever being reversed when said first lever reaches a predetermined position intermediate between said home position and said operating position for suddenly moving said second lever. 

1. A re-winding device for a strip of paper for teleprinters and printing machines in general, including a printing roller over which the paper strip passes for writing thereon, a re-winding roller for rewinding the printed strip, an electric motor drivingly coupled to said rewinding roller, a feeding circuit coupled to said motor and operable to supply drive current thereto, a switch for operating said feeding circuit, and a bar around which the strip forms a loop, wherein the improvement comprises a first lever connected to said bar and oscillating between a pair of positions, a first position of said pair indicating a predetermined minimum length of said loop, a second position indicating a predetermined maximum length of said loop, a cam fixed to said first lever for driving the rotation of a second oscillating lever, one end of said second oscillating lever being connected elastically to one end of an oscillating keeper to operate an actuating button of said switch when said first lever reaches said second position.
 2. A re-winding device in accordance with claim 1 including a circuit for generating a predetermined strip-break indicating signal, said circuit including a second switch cooperating with said first oscillating lever for generating said signal, said first lever assuming a third position different from said first and second positions wherein said strip loop is of maximum length when said strip loop breaks.
 3. A re-winding device as claimed in claim 2 wherein said second switch includes an actuating button cooperating through an element with one end of said cam, said one cam end coming to rest against said element when said first oscillating lever assumes said third position.
 4. A re-winding device as claimed in claim 2 including a feed strip roller carrying said paper strip in a roll in said machine, and means sensitive to the diameter of said feed paper strip roll and cooperating with the actuating button of said second switch for actuating said switch when the diameter of said feed strip roll reaches a predetermined value.
 5. A rewinding device in accordance with claim 4 wherein the means sensitive to the diameter of the strip roll comprise a third oscillating lever, one whose ends cooperate with the outer surface of said feed strip roll and the other end rests on said element cooperating with the actuating button of the second switch.
 6. A re-winding device as claimed in claim 1 comprising a fixed frame integral with the machine and on which there is mounted revolvingly the roller which supports the said feed strip roll, and an oscillating frame hinged to the fixed frame and comprising substantially an upper wall and two lateral flanks said re-winding roller being revolvingly mounted on said oscillating frame.
 7. A re-winding device in accordance with claim 6, including a locking member hinged to the oscillating frame for manually locking said oscillating frame and including a slot located on said locking member to cooperate with a projecting part integral with the fixed frame, a spring being fixed at one end to the lever and arranged to keep the locking member normally against the projecting part of the frame.
 8. A rewinding device in accordance with claim 7, wherein slots are extracted in the lateral flanks of the oscillating frame, said slots being arranged to accommodate the end pins of the rewinding roller.
 9. A re-winding device in accordance with claim 8, including a gear transmission comprising a clutch connecting one of the end pins of the re-winding roller to the motor.
 10. A re-winding device in accordance with claim 9, wherein the clutch comprises at least one frontal tooth extracted on a gear of the transmission and adapted to cooperate with at least one radial projection integral with one end pin of the re-winding roller.
 11. A re-winding device in accordance with claim 10, wherein the said gearing is connected axially, but not torsionally, to a drive element operable manually and arranged to assume a first position in which the clutch is open and a second one position in which the clutch is closed.
 12. A re-winding device in accordance with claim 11, wherein the driving element includes a tooth extracted in it and cooperating with a cam having first and second axial adjacent cavities, a helical spring being arranged which thrusts the said gearing towards the re-winding roller holding said tooth within said cavities.
 13. A re-winding device in accordance with claim 11, wherein the driving element is arranged to co-operate with the locking member of the oscillating frame, so as to prevent the unlocking of the oscillating frame when the clutch is closed.
 14. A re-winding device in accordance with claim 13, wherein said driving element includes a projecting part arranged to place itself on the trajectory of the locking member which drives the unlocking of the frame itself, when the driving element is in said second position in which the clutch is closed.
 15. A rewinding device for a strip of paper for teleprinters and printing machines in general, including a platen roller over which the paper strip passes for writing thereon, said platen roller being rotatable for line spacing said paper strip, a rewinding roller for rewinding the printed paper strip, an electric motor drivingly coupled to said rewinding roller, a switch operable for supplying electric power to said motor, a bar around which the strip forms a loop and reciprocably movable between a pair of positions, a first position of said pair corresponding To a predetermined minimum length of said loop, a second position corresponding to a predetermined maximum length of said loop, a member connected to said bar for concomitant movement, an element shiftable from a home position to an operating position to operate said switch, and intermediate means connecting said member and said element for suddenly shifting said element from said home position to said operating position when said member reaches said second position and from said operating position to said home position when said member reaches said first position.
 16. A re-winding device according to claim 15, wherein said member is formed of a first lever and said element is formed of a second lever fulcrumed on a stationary pivot, said intermediate means including a tension spring connected between two ends of said levers, the rotational force of said spring on said second lever being reversed when said first lever reaches a predetermined position intermediate between said home position and said operating position for suddenly moving said second lever. 